Commit 413643f3 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Andrew Morton
Browse files

mempool: use new mempool KASAN hooks 

Update the mempool code to use the new mempool KASAN hooks.

Rely on the return value of kasan_mempool_poison_object and
kasan_mempool_poison_pages to prevent double-free and invalid-free bugs.

Link: https://lkml.kernel.org/r/d36fc4a6865bdbd297cadb46b67641d436849f4c.1703024586.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7d4847de

mm/mempool.c

+12 −10
Original line number Diff line number Diff line
@@ -112,31 +112,33 @@ static inline void poison_element(mempool_t *pool, void *element) 
}

#endif /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */



static __always_inline void kasan_poison_element(mempool_t *pool, void *element)

static __always_inline bool kasan_poison_element(mempool_t *pool, void *element)

{

	if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)

		kasan_mempool_poison_object(element);

		return kasan_mempool_poison_object(element);

	else if (pool->alloc == mempool_alloc_pages)

		kasan_poison_pages(element, (unsigned long)pool->pool_data,

				   false);

		return kasan_mempool_poison_pages(element,

						(unsigned long)pool->pool_data);

	return true;

}



static void kasan_unpoison_element(mempool_t *pool, void *element)

{

	if (pool->alloc == mempool_kmalloc)

		kasan_unpoison_range(element, (size_t)pool->pool_data);

		kasan_mempool_unpoison_object(element, (size_t)pool->pool_data);

	else if (pool->alloc == mempool_alloc_slab)

		kasan_unpoison_range(element, kmem_cache_size(pool->pool_data));

		kasan_mempool_unpoison_object(element,

					      kmem_cache_size(pool->pool_data));

	else if (pool->alloc == mempool_alloc_pages)

		kasan_unpoison_pages(element, (unsigned long)pool->pool_data,

				     false);

		kasan_mempool_unpoison_pages(element,

					     (unsigned long)pool->pool_data);

}



static __always_inline void add_element(mempool_t *pool, void *element)

{

	BUG_ON(pool->curr_nr >= pool->min_nr);

	poison_element(pool, element);

	kasan_poison_element(pool, element);

	if (kasan_poison_element(pool, element))

		pool->elements[pool->curr_nr++] = element;

}